Comparative analysis between immunoenzyme and microbiological tests for detection of antibiotic residues in milk

Antibiotics have been widely used in dairy farms in an indiscriminate manner, whether for therapeutic purposes, primarily for the cure of mastitis, or incorporated into the feed. Such procedures lead to the presence of antibiotic residues, representing a risk to consumers, and subsequently a serious problem both economically and to public health. This work contributes by developing a comparative analysis between the ELISA methodology ("SNAP (R) test"), microbiological analysis of the reactive system "Delvotest (R)" and the microbiological agar diffusion method using paper disks, in 127 samples of pasteurized milk and UHT (ultra-high temperature), marketed in the State of Parana in 2007. The methods showed different behaviors in relation to the presence of antibiotic residues. We concluded that among the methods analyzed, the "SNAP (R) test" method proved to be the most sensitive; however by not getting a correlation with the other methods, there would be a need to use ultra-sensitive methods such as the method of liquid chromatography and mass spectrometry. The methods that use microorganism as the conventional method (Association of Official Analytical Chemists, 1995 and Albuquerque et al. modified, 1996) and the "Delvotest (R)" present some inherent limitations in the use of the biological method and poor specificity.